“Many customers will have been financially impacted by the coronavirus, so it is concerning to hear that any energy supplier is using debt collectors to place pressure on customers who could be struggling during this difficult time,” said Natalie Hitchins of consumer group Which?

In a statement to the Guardian, Shell Energy (RDSA.L) said that the issuance of a letter from a debt collection company was “a last-resort attempt to engage with a customer and only after we’ve repeatedly asked them to get in contact to see how we can help.”

British Gas (CNA.L) and Ovo Energy, the UK’s largest energy suppliers, told the Guardian that they would continue to use debt collectors, noting that they had instructed them to offer financial help on their behalf.

E.on UK (EOAN.DE) said that, while debt collectors acting on its behalf would continue to pursue long-standing debts, the company would not hand over new customer details to debt collection agencies.

In March, suppliers and the government agreed that customers who may not be in a position to add credit to pre-payment meters could discuss ways to continue being supplied with energy, benefitting four million customers.

More generally, the firms agreed to support any energy customer in financial distress, noting that debt repayments and bills could be “reassessed, reduced or paused where necessary.”

Disconnection of credit meters was also completely suspended under the agreement.

“The guidance is quite clear that energy suppliers must consider whether their customers are in financial difficulty and whether they can offer assistance,” said Ed Dodman, a director at the Energy Ombudsman.

“This is not a carte blanche for customers to avoid paying bills but suppliers should be sensitive to the circumstances of their customers on a case by case basis.”